Description
You can use the "Check invalidity" instruction to check if the value of an operand (<Operand>) is an invalid floating-point number. The check is performed in every program cycle. If the operand value at the time of the query is a valid floating-point number, then the output box will return the signal state "1". In all other cases, the signal state on the output box is "0".
Parameters
The following table shows the parameters of the instruction "Check invalidity":
|
Parameters |
Declaration |
Data type |
Memory area |
Description |
|---|---|---|---|---|
|
<Operand> |
Input |
Floating-point numbers |
I, Q, M, D, L |
Value to be checked. |
For additional information on valid data types, refer to "See also":
Example
The following example shows how the instruction works:
When the value of operand "TagIn_Value" is an invalid floating-point number, the instruction "Move value" is not executed. The "TagOut" operand at the ENO enable output is set to the signal state "0".